Strategies for improving diversity, equity, and inclusion in cardiovascular research: a primer

This paper aims to empower cardiovascular (CV) researchers by promoting diversity, equity, and inclusion (DE&I) principles throughout the research cycle. It defines DE&I and introduces practical strategies for implementation in recruitment, retention, and team dynamics within CV research. Evidence-based approaches supporting underrepresented populations' participation are outlined for each research phase. Emphasizing the significance of inclusive research environments, the paper offers guidance and resources. We invite CV researchers to actively embrace DE&I principles, enhancing research relevance and addressing longstanding CV health disparities.

Perceptions and attitudes toward COVID-19 vaccination among health professional students in Australia: a qualitative study

Using two qualitative data sources: free-text responses to an open-ended question of an online survey and subsequent interviews and focus groups, we explored perceptions and attitudes toward COVID-19 vaccination among health professional students enrolled in Australian universities during the pandemic with data collected from October 2021 to April 2022. Students provided free-text responses to the open-ended question (n = 313) in the online survey and participated in interviews or focus groups (n = 17). Data analysis revealed three themes, including perceptions of COVID-19 seriousness and the risk of contracting the virus, information dissemination, and attitudes toward the vaccine mandate. The study identified evolving perceptions of COVID-19 seriousness among Australian health professional students and their sentiments toward the vaccine mandate. There is a need to ensure the quality of information dissemination related to the vaccine mandate. This may not only support students' uptake of mandatory vaccination but also provide a means for them to address vaccination with healthcare consumers and patients.

Barriers and facilitators to COVID-19 vaccine uptake among Australian health professional students during the pandemic: a nationwide study

Using a cross-sectional online survey we investigated knowledge, attitudes, and risk perception about COVID-19 vaccination and identified factors influencing vaccine uptake among Australian health professional students from October 2021 to January 2022. We analysed data from 1114 health professional students from 17 Australian universities. Most participants were enrolled in nursing programs (n = 958, 86.8%), and 91.6% (n = 858) of the participants received COVID-19 vaccination. Approximately 27% believed COVID-19 was no more serious than seasonal influenza and that they had a low risk of acquiring COVID-19. Nearly 20% disagreed that COVID-19 vaccines in Australia were safe and perceived they were at higher-risk of acquiring COVID infection than the general population. Higher-risk perception viewing vaccination as their professional responsibility, and vaccine mandate strongly predicted vaccination behaviour. Participants consider COVID-19 information from health professionals, government websites, and World Health Organization as the most trusted information sources. The findings highlight that healthcare decision-makers and university administrators need to monitor students' hesitancy with vaccination to improve students' promotion of the vaccination to the general population.

Comparison of six frailty instruments in adults with heart failure: a prospective cohort pilot study

Aim

To compare the frailty prevalence and predictive performance of six frailty instruments in adults with heart failure and determine feasibility of study methods.

Methods and Results

Prospective cohort pilot study. Adults aged 18 years or older with a confirmed diagnosis of heart failure in Sydney, New South Wales, Australia. The Frailty Phenotype; the Survey of Health, Ageing and Retirement in Europe Frailty Instrument (SHARE-FI); St Vincent’s Frailty instrument; St Vincent’s Frailty instrument plus cognition and mood; The Fatigue, Resistance, Ambulation, Illnesses, and Loss of Weight (FRAIL) scale; and the Deficit Accumulation Index were compared. Multiple logistic regression was used to develop six frailty instrument models to evaluate the association between each frailty instrument and composite all-cause rehospitalisation and mortality at 12 months

One hundred and thirty-one patients were included with a mean age of 54 (± 14[SD]). Frailty prevalence ranged from 33-81%. All instruments except one (the FRAIL scale) appeared to signal an increased odds of rehospitalisation and/or mortality, yet these results were non-significant. The six frailty instrument models displayed sensitivity between 88-92% and C-statistic values of 0.71-0.73, suggesting satisfactory discrimination.

Conclusions

The prevalence of frailty varied across six frailty instruments yet was in the higher range despite a ‘younger’ heart failure cohort. Further research is required to confirm the psychometric properties of these instruments for routine clinical use in an adequately powered and more diverse heart failure cohort.

Clinician Estimates of Frailty Compared to Formal Frailty Assessment in Adults With Heart Failure: A Cross-Sectional Analysis

BACKGROUND

Frailty assessment is recommended for patients with heart failure. Despite the availability of instruments to assess frailty, there are no clear recommendations regarding the optimal instrument to use in a heart failure context. This ambiguity combined with a lack of education and resources, often leads clinicians to rely on subjective estimates of frailty, such as 'the end-of-the-bed' or 'eyeball' test.

AIM

To examine the association between clinician-estimated frailty and formal frailty assessment in adults with heart failure.

METHODS

Cross-sectional analysis of the FRAilty MEasurement in Heart Failure (FRAME-HF) study.

PARTICIPANTS

(1) Adults aged ≥18 years in the outpatient heart failure clinic and cardiology ward; (2) and cardiovascular clinicians (nurses, physicians, and allied-health professionals). Following participant recruitment, cardiovascular clinicians were asked to rate the participant's frailty status based on their routine clinical assessment as either: frail, pre-frail, or non-frail, which was then compared to a formal frailty assessment using a modified version of the Frailty Phenotype. The association between clinician-estimated frailty and formal frailty assessment were examined using a weighted Kappa statistic and Spearman's correlation coefficient.

RESULTS

A total of 75 patients and 39 clinicians were recruited, producing 194 paired frailty assessments. Mean age of the patients was 54 (±13) years. Correlation of pooled clinician-estimated frailty to formal frailty was fair (0.52, p=0.00). Correlation was highest between allied-health estimated frailty and formal frailty (0.70, p=0.00). Agreement between pooled clinician-estimated frailty and formal frailty was fair (0.33) and was highest between allied health-estimated frailty and formal frailty (0.45).

CONCLUSION

Subjective clinician-estimated frailty is not a reliable replacement for formal frailty assessment in adults with heart failure, underscoring the need for assessment using a valid and reliable instrument.

1443 Comparison of Outcomes Between Immediate Direct-to-Implant Breast Reconstruction versus Two-Stage Implant Breast Reconstruction; a Systematic Review and Meta-analysis

Background

Direct-to-implant (DTI) breast reconstruction is increasingly performed as the preferred method of immediate breast reconstruction following mastectomy. The proposed advantages of DTI over two-stage tissue expander (TE)/implant reconstruction relate to fewer surgical procedures. This systematic review and meta-analysis aims to evaluate the safety and efficacy of DTI versus conventional TE/implant breast reconstruction.

Method

A systematic review was performed (PubMed, Embase, Scopus) to identify relevant studies that compared outcomes between DTI and TE/Implant reconstructions. Publications up to October 2020 were included. The primary outcome was overall complication rate. Secondary outcomes included infection rate and implant loss.

Results

Nineteen studies, including 32,971 implant-based breast reconstructions, were analysed. Median age was 48 years. Mean BMI was 25.9. There was no statistically significant difference between the two groups. Duration of follow up ranged from 1-60 months. Overall complications were significantly more likely to occur in the DTI group (OR 1.81 [1.17-2.79]). Overall complications refers to all reported complications including seroma, haematoma, would dehiscence, infection, skin necrosis and capsular contracture. Implant loss was also significantly higher in the DTI cohort (OR 1.31 [1.12-1.78]). There was no significant difference in infection rates between the two groups. Subgroup analyses, focusing on high-powered multicentre studies showed that the risks of overall complications were significantly higher in the DTI group (OR 1.51 [1.06-2.14]).

Conclusions

This meta-analysis demonstrates significantly greater risk of complications and implant loss in the DTI breast reconstruction group. These findings serve to aid both patients and clinicians in the decision-making process regarding implant reconstruction following mastectomy

mHealth education interventions in heart failure

BACKGROUND

Heart failure (HF) is a chronic disease with significant impact on quality of life and presents many challenges to those diagnosed with the condition, due to a seemingly complex daily regimen of self-care which includes medications, monitoring of weight and symptoms, identification of signs of deterioration and follow-up and interaction with multiple healthcare services. Education is vital for understanding the importance of this regimen, and adhering to it. Traditionally, education has been provided to people with heart failure in a face-to-face manner, either in a community or a hospital setting, using paper-based materials or video/DVD presentations. In an age of rapidly-evolving technology and uptake of smartphones and tablet devices, mHealth-based technology (defined by the World Health Organization as mobile and wireless technologies to achieve health objectives) is an innovative way to provide health education which has the benefit of being able to reach people who are unable or unwilling to access traditional heart failure education programmes and services.

OBJECTIVES

To systematically review and quantify the potential benefits and harms of mHealth-delivered education for people with heart failure.

SEARCH METHODS

We performed an extensive search of bibliographic databases and registries (CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, IEEE Xplore, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) Search Portal), using terms to identify HF, education and mHealth. We searched all databases from their inception to October 2019 and imposed no restriction on language of publication.

SELECTION CRITERIA

We included studies if they were conducted as a randomised controlled trial (RCT), involving adults (≥ 18 years) with a diagnosis of HF. We included trials comparing mHealth-delivered education such as internet and web-based education programmes for use on smartphones and tablets (including apps) and other mobile devices, SMS messages and social media-delivered education programmes, versus usual HF care.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risks of bias, and extracted data from all included studies. We calculated the mean difference (MD) or standardised mean difference (SMD) for continuous data and the odds ratio (OR) for dichotomous data with a 95% confidence interval (CI). We assessed heterogeneity using the I² statistic and assessed the quality of evidence using GRADE criteria.

MAIN RESULTS

We include five RCTs (971 participants) of mHealth-delivered education interventions for people with HF in this review. The number of trial participants ranged from 28 to 512 participants. Mean age of participants ranged from 60 years to 75 years, and 63% of participants across the studies were men. Studies originated from Australia, China, Iran, Sweden, and The Netherlands. Most studies included participants with symptomatic HF, NYHA Class II - III. Three studies addressed HF knowledge, revealing that the use of mHealth-delivered education programmes showed no evidence of a difference in HF knowledge compared to usual care (MD 0.10, 95% CI -0.2 to 0.40, P = 0.51, I² = 0%; 3 studies, 411 participants; low-quality evidence). One study assessing self-efficacy reported that both study groups had high levels of self-efficacy at baseline and uncertainty in the evidence for the intervention (MD 0.60, 95% CI -0.57 to 1.77; P = 0.31; 1 study, 29 participants; very low-quality evidence).Three studies evaluated HF self-care using different scales. We did not pool the studies due to the heterogenous nature of the outcome measures, and the evidence is uncertain. None of the studies reported adverse events. Four studies examined health-related quality of life (HRQoL). There was uncertainty in the evidence for the use of mHealth-delivered education on HRQoL (MD -0.10, 95% CI -2.35 to 2.15; P = 0.93, I² = 61%; 4 studies, 942 participants; very low-quality evidence). Three studies reported on HF-related hospitalisation. The use of mHealth-delivered education may result in little to no difference in HF-related hospitalisation (OR 0.74, 95% CI 0.52 to 1.06; P = 0.10, I² = 0%; 3 studies, 894 participants; low-quality evidence). We downgraded the quality of the studies due to limitations in study design and execution, heterogeneity, wide confidence intervals and fewer than 500 participants in the analysis.

AUTHORS' CONCLUSIONS

We found that the use of mHealth-delivered educational interventions for people with HF shows no evidence of a difference in HF knowledge; uncertainty in the evidence for self-efficacy, self-care and health-related quality of life; and may result in little to no difference in HF-related hospitalisations. The identification of studies currently underway and those awaiting classification indicate that this is an area of research from which further evidence will emerge in the short and longer term.

Costs Before and After Left Ventricular Assist Device Implant and Preceding Heart Transplant: A Cohort Study

BACKGROUND

Up to 50% of heart transplant candidates require bridging with left ventricular assist devices (VAD). This study describes hospital activity and cost 1 year preceding and 1 year following VAD implant (pre-VAD) and for the year before transplant (pre-HTX). The sample comprises an Australian cohort and is the first study to investigate costs using both institutional and linked administrative data.

METHODS

Institutional activity was established for 77 consecutive patients actively listed for transplant between 2009 and 2012. Costs were sourced from the institution or Australian refined diagnosis groups (arDRGs) and the National Efficient Price for admissions to other public and private institutions. Data from 25/77 VAD recipients were analysed and compared with data from 52/77 pre-transplant patients. Total and per day at risk costs were assessed, as well as totals per resource.

RESULTS

Fifty per cent (50%) of the hospital costs in the pre-VAD year occurred during admission of VAD implant. Sixty-four per cent (64%) of costs in the pre-HTX and 38% in the pre-VAD period occurred outside the implanting centre. Costs in the year prior to VAD, $97,565 (IQR $86,907-$153,916), were significantly higher than costs accrued in the year prior to transplant, $40,250 ($13,493-$81,260), p < 0.0001. Once discharged, costs per day at risk for post-VAD patients approximated those from the pre-admission period, p = 0.16 and in the more clinically stable pre-HTX cohort, p = 0.08.

CONCLUSION

Compared with the year prior, VAD implant stabilised hospital cost in patients discharged home. A high proportion of the hospital costs in the pre-implant year occur outside the implanting centre and should be considered in economic models assessing the impact of VAD implant.

Evaluating the convergent and discriminant validity of three versions of the frailty phenotype in heart failure: results from the FRAME-HF study

BACKGROUND

Frailty is an important predictive measure of mortality and rehospitalisation in people with heart failure. To date, there are no frailty instruments validated for use in people with heart failure.

AIM

The aim of this study was to evaluate the convergent and discriminant validity of three versions of the frailty phenotype in those with heart failure.

METHODS

A single site, prospective cohort study was undertaken among individuals with a confirmed diagnosis of heart failure. Frailty was assessed concurrently using three versions of the frailty phenotype: the original frailty phenotype and two modified versions; the Survey of Health, Ageing and Retirement in Europe frailty instrument (SHARE-FI) and the St Vincent's frailty instrument. Convergent and discriminant validity were assessed by reporting the correlations between each version and related heart failure subconstructs, and by evaluating the ability of each version to discriminate between normal and abnormal scores of other physical and psychosocial scales specific to heart failure-related subconstructs.

RESULTS

The New York Heart Association classes were moderately correlated with the St Vincent's frailty instrument (r=0.47, P⩽0.001), SHARE-FI (r=0.42, P⩽0.001) and the frailty phenotype (r=0.42, P⩽0.001). The SHARE-FI and the St Vincent's frailty instrument were both able to discriminate consistently between normal and abnormal scores in three out of five of the physical and psychosocial subconstructs that were assessed. The SHARE-FI was also able to discriminate between inpatients and outpatients who were classified as frail.

CONCLUSIONS

Both the SHARE-FI and the St Vincent's frailty instrument displayed good convergent and discriminant validity.

The approach to an isolated close anterior margin in breast conserving surgery

INTRODUCTION

Although close radial margins after breast-conserving surgery routinely undergo re-excision, appropriate management of patients with close anterior margins remains a topic of controversy. An increasing body of literature suggests that re-excision of close anterior margins yields low rates of residual malignancy and may only be necessary in selected patients. The aim of this study was to examine the management of close anterior margins after breast conserving surgery in a single institution and to analyse the rate of residual disease in re-excised anterior margins.

METHODS

All patients having breast conserving surgery at St Vincent's University Hospital from January 2008 to December 2012 were reviewed retrospectively. Data collected included patient demographics, tumour characteristics, margin positivity, re-excision rates and definitive histology of the re-excision specimens. A close margin was defined as les than 2 mm.

RESULTS

A total of 930 patients were included with an average age of 65 years (range 29-94 years). Of these, 121 (13%) had a close anterior margin. Further re-excison of the anterior margin was carried out in 37 patients (30.6%) and a further 16 (13.2%) proceeded to mastectomy. Residual disease was found in 18.5% (7/36) of those who underwent re-excision and 7/16 (43.75%) of those who underwent mastectomy. Overall, 11.57% (14/121) of patients with close anterior margins were subsequently found to have residual disease.

CONCLUSION

The low yield of residual disease in re-excised anterior margins specimens supports the concept that routine re-excision of close anterior margins is not necessary. Further research is required to definitively assess its influence on the risk of local recurrence.

Adaptation and coping in patients living with an LVAD: A metasynthesis

OBJECTIVE

To synthesize information supporting coping and adaptation of LVAD patients and to identify opportunities for future interventions.

BACKGROUND

Left Ventricular Assist Device (LVAD) patients demonstrate improvements in quality of life and functional status, but qualitative research has not been meaningfully integrated.

METHODS

Qualitative meta-synthesis using Lazarus and Folkmans' Transactional Model of stress and coping.

RESULTS

Four distinct stages of adaptation were identified: Pre-LVAD, Implant Hospitalization, Early Home Adaptation and Late Home Adaptation. Each stage includes tasks in physical, psychological and social domains. Two themes emerged: 1) Primary Appraisal: Every stage is a new challenge and 2) Secondary Appraisal: Routines are achievable, emotions are more difficult.

CONCLUSIONS

Emotional challenges including fear and anxiety related to life-limiting illness and changed social roles need to be honestly addressed. Individuals living with LVAD achieve a sense of independence, enjoy social interactions and meaningful activities through addressing practical and emotional problems to facilitate coping.

Abstract P1-07-09: Retrospective cohort study of patients (pts) diagnosed with breast cancer (BC) &lt;40 yrs: 2000 to 2015⟨

Background

Young women (&lt;40 yrs) with breast cancer (YWBC) account for 7-12% of BC diagnoses. BC is the leading cause of cancer death in this group (G). Age-specific data on outcome and appropriate treatment (Rx) are lacking. YWBC appear to have more biologically aggressive subtypes and a higher risk of relapse and death. We studied the clinico-pathological (ClinPath) characteristics in YWBC, examining how outcomes/Rx have evolved.

Methods

YWBC were identified from pathology databases at 2 tertiary centers. Pts were divided into 2 cohorts: BC diagnoses from 2000-2007 (G1) and 2008-2015 (G2). ClinPath and Rx data were retrieved from clinical, radiology and histology databases. Statistical analysis was performed using SPSS.

Results

We identified 347 pts. Tumor features are shown in Table I. Median age is 36 (23-39). By histology, 90.8% (n=315) had invasive ductal carcinoma, 53.1% (n=181) had Grade III BC and 56.3% (n=171) had lymphovascular invasion. Pregnancy-associated BC occurred in 10.7% (n=34). Mastectomy (MX) was performed in 53% (n=176) and axillary lymph node clearance (ALNC) in 63.8% (n=192 [G1: 84.3% vs. G2: 48.6%, p&lt;0.001]).

Table 1Tumor features Group 1 (n=149)Group 2 (n=198)Total (n=347)p-valueMedian tumor size (mm) 252222.5p=0.115Node positivity 88 (60.3%)100(51.5%)188 (55.3%)p=0.109Median node count 4 (1-44)1 (1-30)2 (1-44)p&lt;0.001StageI  99(29%)  II  148 (43.3%)  III  70 (20.5%)  IV  23(7.3%) Biomarker status*ER+/HER2-76 (53.1%)120 (60.6%)196 (56%)p=0.086 HER2+41 (28.7%)45 (22.8%)86 (27%)p=0.031 Triple negative (TN)26 (18.2%)33 (16.8%)59 (17%)p=0.291* Missing data n=6

Rx characteristics are shown in Table 2. 85 pts received neo-adjuvant therapy (NAT); 48.3% (n=41) ER+/HER2-, 27% (n=23) HER2+ and 24.7% (n=21) TNBC. Pts receiving NAT in G2 trended towards improved pCR rate (G2: 24.6% vs G1: 8.3%, p=0.057). Endocrine Rx alone was received by 9.8% (n=22); 13.6% (n=18) in G2 vs 4.3% (n=4) in G1. OncotypeDx(ODx) was used in 23 pts (14.9%) (median score 17), 1 had a DR (ODx Score = 18).

Table 2Tx characteristics n=347 Chemotherapy Total300(86.4%)  NAT85 (28.3%)Pathological Complete Response (pCR)* pCR (n=16, 19.8%)No pCR (n=65, 80.2%) ER+/HER2-18.8%(n=3)53.9% (n=35) HER2+/ER+18.8%(n=3)13.8% (n=9) HER2+/ER-31.2% (n=5)9.2% (n=6) TNBC31.2%(n=5)23.1%(n=15)Local relapse 1 (6.2%)1(1.5%)Distant relapse (DR) 022(33.8%)*Data incomplete n=4

DR occurred in 50 pts (16%), including 13 (20.3%) HER2+ pts. Of note, 92.3% (n=12) of these were in G1. Relapse rates (RR) in TN and ER+/HER- pts were 19.6% (n=11) and 13.7% (n=26) respectively. There was a higher RR in G1 (34.8% vs 11.4%, p&lt;0.001). Overall survival in pts with stage IV dx was 32 mos in G1 and 48 mos in G2.

Conclusion

In line with existing data, locally advanced dx is more prevalent in YWBC. MX and ALNC rates were high and most received multimodal Rx. The extent of axillary surgery declined. Pts in G2 had lower volume BC at diagnosis suggesting increasing awareness. TN and HER2+ subtypes accounted for a slightly higher proportion of BC cases. Pts with PCR had better outcomes. Only 16% relapsed with metastatic dx. The impact of HER2 Rx is highlighted by reduced RR in HER2+ G2 pts. Outcomes were unchanged in pts with ER+/HER2- and TNBC. These remain a priority for future research.

Citation Format: Greally M, Kielty J, Das G, Malouf C, O'Riordan L, Coleman N, Quinn C, McDermott E, Gullo G, Kelly C, Crown J, Prichard R, Walshe J. Retrospective cohort study of patients (pts) diagnosed with breast cancer (BC) &lt;40 yrs: 2000 to 2015⟨. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-07-09.

Monitoring the efficacy of drugs for neglected tropical diseases controlled by preventive chemotherapy

In the last decade, pharmaceutical companies, governments and global health organisations under the leadership of the World Health Organization (WHO) have pledged large-scale donations of anthelmintic drugs, including ivermectin (IVM), praziquantel (PZQ), albendazole (ALB) and mebendazole (MEB). This worldwide scale-up in drug donations calls for strong monitoring systems to detect any changes in anthelmintic drug efficacy. This review reports on the outcome of the WHO Global Working Group on Monitoring of Neglected Tropical Diseases Drug Efficacy, which consists of three subgroups: (i) soil-transmitted helminthiases (ALB and MEB); (ii) onchocerciasis and lymphatic filariasis (IVM); and (iii) schistosomiasis (PZQ). Progress of ongoing work, challenges and research needs for each of the four main drugs used in helminthic preventive chemotherapy (PC) are reported, laying the ground for appropriate implementation of drug efficacy monitoring programmes under the co-ordination and guidelines of the WHO. Best practices for monitoring drug efficacy should be made available and capacity built as an integral part of neglected tropical disease (NTD) programme monitoring. Development of a disease-specific model to predict the impact of PC programmes, to detect outliers and to solicit responses is essential. Research studies on genetic polymorphisms in relation to low-efficacy phenotypes should be carried out to identify markers of putative resistance against all NTD drugs and ultimately to develop diagnostic assays. Development of combination and co-administration of NTD drugs as well as of new drug entities to boost the armamentarium of the few drugs available for NTD control and elimination should be pursued in parallel.

Emerging therapies for thyroid carcinoma

Thyroid carcinoma is the most commonly diagnosed endocrine malignancy. Its incidence is currently rising worldwide. The discovery of genetic mutations associated with the development of thyroid cancer, such as BRAF and RET, has lead to the development of new drugs which target the pathways which they influence. Despite recent advances, the prognosis of anaplastic thyroid carcinoma is still unfavourable. In this review we look at emerging novel therapies for the treatment of well-differentiated and medullary thyroid carcinoma, and advances and future directions in the management of anaplastic thyroid carcinoma.

Origin and history to date of the World Association for the Advancement of Veterinary Parasitology (WAAVP) African Foundation

The origin of the World Association for the Advancement of Veterinary Parasitology (WAAVP) African Foundation is described. The 16th WAAVP Conference held in South Africa in 1997 generated a surplus of ZAR 430 460 (US$ 70 116). This was invested and a foundation established to manage the fund with the intention of using it to the mutual advantage of the WAAVP and African veterinary parasitologists. To date, more than 110 scholarship applications have been screened, and 51 full and partial scholarships awarded to young African veterinary parasitologists to attend subsequent biennial WAAVP Conferences. This investment has grown into a very successful endowment currently valued at US$ 206 553. This article is written in response to many queries across the globe about the origin of this fund and how it has been invested, managed, sustained and utilised.

Management of spontaneous rupture of the oesophagus (Boerhaave’s syndrome): Single centre experience of 18 cases

BACKGROUND

Spontaneous oesophageal rupture (Boerhaave's syndrome) is rare, and carries a high attendant risk of mortality.

METHODS

A retrospective eight-year review from a tertiary unit.

RESULTS

Eighteen patients were managed, with a mean age of 57 (39 - 88 years). Eight patients presented early and underwent surgery, seven with primary closure and one with exclusion and diversion. There was one death in this group. Ten patients were managed conservatively. In this group, two underwent an oesophagectomy because of failed conservative measures, and four had an endoprosthesis inserted. One patient died in this group on the first admission, but two patients with stents in situ died from massive bleeding relating to an aorto-oesophageal fistula at 39 days and 189 days respectively following presentation.

CONCLUSIONS

Surgical intervention remains the gold standard when the diagnosis is made early. For late diagnoses, this series suggests caution in the use of endoprostheses.

Influence of verapamil on the pharmacokinetics of the antiparasitic drugs ivermectin and moxidectin in sheep

P-Glycoprotein (P-GP) is a transport protein that participates in the mechanism of active secretion of different molecules from the bloodstream to the gastrointestinal tract. The aim of the current work was to evaluate the effect of verapamil, a P-GP substrate, on the pharmacokinetic behaviour of the anthelmintics ivermectin and moxidectin in sheep. Thirty-two sheep were divided into four groups and treated orally with either ivermectin or moxidectin alone (200 micro g/kg) or co-administered with verapamil at 3 mg/kg (three times at 12 h intervals). Blood samples were collected over 30 days post-treatment and plasma was analysed to determine ivermectin and moxidectin concentrations by HPLC. The ivermectin peak concentration was significantly higher ( P=0.048) after ivermectin plus verapamil, compared with the ivermectin alone treatment. Ivermectin plasma availability was significantly higher following co-administration ( P=0.022). Verapamil had no effect on the kinetics of moxidectin. The significant alteration in the plasma disposition of ivermectin in sheep induced by verapamil, possibly due to interference with a P-GP-mediated elimination mechanism, may have an important impact on efficacy against resistant- or rate-limiting-parasites and on the persistency of its antiparasitic activity.

Genetic variability following selection of Haemonchus contortus with anthelmintics

Genetic diversity in nematodes leads to variation in response to anthelmintics. Haemonchus contortus shows enormous genetic diversity, allowing anthelmintic resistance alleles to be rapidly selected. Anthelmintic resistance is now a widespread problem, especially in H. contortus. Here, I compare the genes involved in anthelmintic resistance in H. contortus with those that confer susceptibility or resistance on the free living nematode Caenorhabditis elegans. I also discuss the latest knowledge of genes associated with resistance to benzimidazoles, levamisole and the macrocyclic lactones and the need for DNA markers for anthelmintic resistance.

The role of molecular biology in veterinary parasitology

The tools of molecular biology are increasingly relevant to veterinary parasitology. The sequencing of the complete genomes of Caenorhabditis elegans and other helminths and protozoa is allowing great advances in studying the biology, and improving diagnosis and control of parasites. Unique DNA sequences provide very high levels of specificity for the diagnosis and identification of parasite species and strains, and PCR allows extremely high levels of sensitivity. New techniques, such as the use of uniquely designed molecular beacons and DNA microarrays will eventually allow rapid screening for specific parasite genotypes and assist in diagnostic and epidemiological studies of veterinary parasites. The ability to use genome data to clone and sequence genes which when expressed will provide antigens for vaccine screening and receptors and enzymes for mechanism-based chemotherapy screening will increase our options for parasite control. In addition, DNA vaccines can have desirable characteristics, such as sustained stimulation of the host immune system compared with protein based vaccines. One of the greatest threats to parasite control has been the development of drug resistance in parasites. Our knowledge of the basis of drug resistance and our ability to monitor its development with highly sensitive and specific DNA-based assays for 'resistance'-alleles will help maintain the effectiveness of existing antiparasitic drugs and provide hope that we can maintain control of parasitic disease outbreaks.

Ivermectin resistance in nematodes may be caused by alteration of P-glycoprotein homolog

Resistance to ivermectin and related drugs is an increasing problem for parasite control. The mechanism of ivermectin resistance in nematode parasites is currently unknown. Some P-glycoproteins and multidrug resistance proteins have been found to act as membrane transporters which pump drugs from the cell. A disruption of the mdrla gene, which encodes a P-glycoprotein in mice, results in hypersensitivity to ivermectin. Genes encoding members of the P-glycoprotein family are known to exist in nematodes but the involvement of P-glycoprotein in nematode ivermectin-resistance has not been described. Our data suggest that a P-glycoprotein may play a role in ivermectin resistance in the sheep nematode parasite Haemonchus contortus. A full length P-glycoprotein cDNA from H. contortus has been cloned and sequenced. Analysis of the sequence showed 61-65% homology to other P-glycoprotein/multidrug resistant protein sequences, such as mice, human and Caenorhabditis elegans. Expression of P-glycoprotein mRNA was higher in ivermectin-selected than unselected strains of H. contortus. An alteration in the restriction pattern was also found for the genomic locus of P-glycoprotein derived from ivermectin-selected strains of H. contortus compared with unselected strains. P-glycoprotein gene structure and/or its transcription are altered in ivermectin-selected H. contortus. The multidrug resistance reversing agent, verapamil, increased the efficacy of ivermectin and moxidectin against a moxidectin-selected strain of this nematode in jirds (Meriones unguiculatus). These data indicate that a P-glycoprotein may be involved in resistance to ivermectin and other macrocyclic lactones in H. contortus.

Application of molecular biology in veterinary parasitology

The number of applications of molecular biology in veterinary parasitology is increasing rapidly. The techniques used with eukaryotic cells are generally applicable to the study of parasites and their hosts. The polymerase chain reaction is particularly important for identification and diagnosis of parasites, as well as for many other applications. With species and type specific probes or primers, sensitivities and specificities unheard of with conventional techniques can be achieved. The accumulation of more information on the DNA sequences of parasites will reveal many more unique sequences which can be used for identification, diagnosis, molecular epidemiology, vaccine development and for studying the evolutionary biology and the physiology of parasites and the host-parasite relationship. Similarly, the completion of genome projects on host organisms will greatly assist efforts to select for hosts that are genetically resistant to parasite infection. The study of the molecular biology of antiparasitic drug receptors, potential targets for chemotherapy, and the molecular genetics of drug resistance will allow molecular screens to be used with combinatorial chemistry in the search for new antiparasitic drugs, improvements to existing chemotherapeutic families and better diagnosis and monitoring of drug resistance. While there is a proliferation of molecular biology techniques, the availability of simple kits and of automated techniques and services for sequencing, library construction and oligonucleotide synthesis and other procedures is making it easier for non-specialists to apply many of the common techniques of molecular biology. Molecular biology and the benefits from its application are relevant for veterinary parasitologists in developing countries as well as developed countries and we should introduce aspects of molecular biology to the teaching and training of veterinary parasitologists.

Anthelmintic resistance

Anthelmintic resistance is widespread in nematode parasites of sheep, goats and horses. Resistance is also developing in nematode parasites of cattle and has been detected in pig parasites. Benzimidazole, levamisole/morantel and ivermectin resistances occur in nematodes of sheep and goats and closantel resistance has been found in Haemonchus contortus. Anthelmintic resistance is likely to develop wherever anthelmintics are frequently used and be detected if it is investigated. Worm count or egg count reduction after treatment are useful for the detection of all types of anthelmintic resistances. More economical, faster and more sensitive in vitro assays for the detection of anthelmintic resistance have been developed. Some, such as the egg hatch assay are specific for a particular class of anthelmintic, whilst others such as larval development assays can be used with most anthelmintics. Improvements in our understanding of the biochemistry and molecular genetics of anthelmintic actions should lead to the development of more sensitive assays for the detection of anthelmintic resistance in individual nematodes. Levamisole/morantel resistance appears to be associated with alterations in cholinergic receptors in resistant nematodes. Ivermectin appears to act by binding to a glutamate receptor of a membrane chloride channel. This receptor has been expressed in vitro so that further studies of the interaction of ivermectin with this receptor and its possible alteration in ivermectin resistance will be feasible. Benzimidazole resistance in nematodes and fungi appears to be associated with an alteration in beta-tubulin genes which reduces or abolishes the high affinity binding of benzimidazoles for tubulin in these organisms. This knowledge can be exploited for DNA probes for benzimidazole resistance/susceptibility in individual organisms.

Characterization and biological activities of anti-Brugia pahangi tubulin monoclonal antibodies

Three monoclonal antibodies (mAb) specific to beta-tubulin were used to investigate the heterogeneity of tubulins from nematodes and mammals. Western blot analysis of one-dimensional SDS-PAGE showed that anti-Brugia pahangi tubulin mAb 1B6 and P3D react with epitope(s) specific to nematode beta-tubulin and recognize tubulin from adults and microfilariae of B. pahangi, adult B. malayi and Dirofilaria immitis, eggs of Haemonchus contortus and adult Ascaris suum. However, the same mAb did not recognize tubulin from trophozoites of Giardia lamblia, pig brain or 3T3 mouse fibroblast cells. In two-dimensional SDS-PAGE, mAb 1B6 recognized one isoform of beta-tubulin and mAb P3D recognized two beta-tubulin isoforms. Limited proteolysis showed that mAb 1B6 reacted with the amino-terminal fragments of beta-tubulin. In contrast, mAb P3D recognized the carboxy-terminal fragments of beta-tubulin. In ELISA, mAb P3D reacted with an 18 amino acid peptide corresponding to residues 430-448 of B. pahangi beta-tubulin. These observations confirm that the epitope of mAb P3D is located on the extreme carboxy-terminal region. Immunogold labelling of adult B. pahangi sections with mAb P3D revealed the presence of beta-tubulin isoforms in the cuticle, hypodermal layer and somatic muscle blocks of B. pahangi. Under in vitro conditions, mAb P3D caused 80% reduction in worm viability, during exposure over 48 h.